Personal computer (PC) systems are available in many different configurations as a consequence of the many different brands and types of components and accessories available for PC systems. These different components include, but are not limited to, memory, disk drives, hard drives, modems, sound units, and audio/video tuners. Therefore, when a consumer orders or purchases a PC, they are able to specify a custom system by specifying the amount and type of memory, the size, type, and number of disk drives, the size of the hard drive, the type and speed of modem, the type of sound unit, and the type of tuner if a tuner is desired.
These build-to-order systems can be problematic for the PC manufacturer. Typically, the PC manufacturer markets and produces a basic system. Following receipt of an order, these basic systems are reconfigured to the individual purchaser's specifications and then shipped. This process of reconfiguring a previously produced system takes additional time and causes the PC manufacturer to incur additional cost and risk. The additional cost and risk arises because the more these systems are handled the higher the probability for broken connections, misinstalled components, and misconfigured systems.
As a result of the large number and variety of computer systems and components available in the marketplace, consumers are constantly performing their own system upgrades, upgrades that involve swapping out PC components, and installing new PC components in their own systems. While these swaps and installations are feasible, they involve some technical knowledge on the part of the consumer making the installation. While these swaps and installations require the consumer to open up their PC systems and remove and replace components, the risk is high for misinstallation or broken wires or connections while one is rummaging around inside their PC.
Consequently, there is a requirement for a modular PC system in which a base unit is supplemented with additional modular components that include, but are not limited to, memory, disk drives, hard drives, modems, and tuners. Therefore, the modular PC system would be analogous to the modular audio/video systems currently on the market thereby allowing the consumer to purchase particular peripheral components like compact disk players and tape players for connection to and use with a base unit, or receiver.
The problem that inheres in a modular PC system configuration is a cabling problem. For example, the typical computer system user will likely require a memory component, at least two disk drive components, a hard drive component, and a modem component. Each of these separate components is required to have power supply connections and to have electrical signal connections to the base unit. When external cabling is used a problem is encountered in that the number of cables in this system becomes unmanageable. This type of modular system and the problem encountered with connections between components is again analogous to the typical stereo system.
Prior art computer manufacturers have used two methods for dealing with this problem. In one prior art computer server system, a vertical riser card is coupled to the computer motherboard of each component. The vertical riser card is configured internally to run vertically through the middle of the component housing and is accessed through an opening in the top and the bottom of the component housing. In this manner, components are coupled together by placing them on top of one another and connecting the riser cards of each component. The problem with this system is that the computer system bus resided on the riser card making this alternative very expensive, and provided only limited expandability.
Another prior art computer system uses rigid external cables between disk drive components. The rigid cables contain all of the cables necessary for connection of the components in a single rigid housing having connectors spaced so that all components could be supported with connections when stacked. One rigid cable supplied power to all of the components, and another rigid cable supplied the small computer system interface (SCSI) bus interconnect for the components. This system, while only supporting disk drive components, does not eliminate the problem of the external cable connections, it only serves to localize the cables. Consequently, there is a requirement for an interconnection system that connects a number of modular electronic components using simple inexpensive internal connections between components instead of coupling the component buses or using multiple external cables.